The human colon is colonised by a wide range of bacteria having both positive and negative effects on the gut's physiology, as well as having other systemic influences. The predominant groups of bacteria found in the colon include Bacteroides species, in particular Bifidobacteria, Eubacteria, Clostridia and Lactobacilli. These bacteria have fluctuating activities in response to substrate availability, redox potential, pH, O2 tension and their distribution in the colon. In general intestinal bacteria can be divided into species exerting either potentially harmful or beneficial effects on their host. Pathogenic effects (which may be caused by Clostridia or Bacteroides, for example) include diarrhoea, infections, liver damage, carcinogenesis and intestinal putrefaction. Health-promoting effects may be induced through the inhibition of the growth of harmful bacteria, the stimulation of immune functions, improvements in the digestion and absorption of essential nutrients and the synthesis of vitamins. An increase in the numbers and/or activities of bacterial groups (such as Bifidobacteria and Lactobacilli) that may have health promoting properties is desirable.
Concerning the specific case of infants, immediately before birth, the gastrointestinal tract of an infant is thought to be sterile. During the process of birth, it encounters bacteria from the digestive tract and skin of the mother and starts to become colonised. Large differences exist with respect to the composition of the gut microbiota in response to the infant's feeding. The faecal flora of breast-fed infants includes appreciable populations of bifidobacteria with some Lactobacillus species, whereas formula-fed infants have more complex microbiota, with Bifidobactera species and Bacteroides species, Clostridia and Streptococci being usually present. After weaning, a pattern of gut microbiota resembling that of an adult pattern becomes established.
Mother's milk is recommended for all infants. However, in some cases breastfeeding is inadequate or unsuccessful for medical reasons or because of mother choice not to breast-feed. Infant formulae have been developed for these situations.
One approach to promote the numbers and/or activities of beneficial bacteria in the colon is the addition of prebiotics to foodstuffs. A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, thereby improving the host's health. Such ingredients are non-digestible in the sense that they are not broken down and absorbed in the stomach or small intestine and thus pass intact to the colon where they are selectively fermented by the beneficial bacteria. Examples of prebiotics include certain oligosaccharides, such as fructooligosaccharides (FOS) and galactooligosaccharides (GOS).
Human milk is known to contain a larger amount of indigestible oligosaccharides than most other animal milks. In fact, indigestible oligosaccharides represent the third largest solid component (after lactose and lipids) in breast milk, occurring at a concentration of 12-15 g/I in colostrum and 5-8 g/I in mature milk. Human milk oligosaccharides are highly resistant to enzymatic hydrolysis, indicating that these oligosaccharides may display essential functions not directly related to their caloric value.
As the understanding of the composition of human milk improves, it has also been proposed to add prebiotics to infant formula. Various infant formulae supplemented with prebiotics such as mixtures of fructooligosacccharides and galactooligosaccharides, for example, are commercially available. However, such mixtures provide only an approximation to the mixture of oligosaccharides present in human milk. Over 100 different oligosaccharide components have been detected in human milk, some of which have not yet been detected, or have been detected only in small quantities, in animal milks such as bovine milk. Some sialylated oligosaccharides and fucosylated oligosaccharides are present both in bovine milk and in colostrum, but only in very small quantities.
EP 0 975 235 B1 from Abbott Laboratories describes a synthetic nutritional composition comprising one or more human milk oligosaccharides, wherein the HMOs in the composition are chosen among a group of eight HMOs (3-fucosyllactose, lacto-N-fucopentaose III, lacto-N-fucopentaose II, difucosyllactose, 2′-fucosyllactose, lacto-N-fucopentaose I, lacto-N-neotetraose and lacto-N-fucopentaose V) wherein said composition is intended for cases of normal, healthy infants, children, adults or subjects having specialized needs such as those that accompany certain pathological conditions. This European patent states that, generally speaking, oligosaccharides protect infants from viral and bacterial infections of the respiratory, gastrointestinal and uro-genital tracts.
An object of the present invention is to provide an oligosaccharide mixture which is effective as a prebiotic, particularly in the human gut.
There is a need for a food product, especially targeted at babies, infants and/or new born infants, that help securing a normal immune or inflammation status or mitigate or reduce the effect of food allergies.
There is a need for a food product that provides the above benefits while preserving a balanced normal metabolism in the individual.
There is a need for an improvement of human gut conditions, by a non-drug-based intervention that is compatible with fragile individuals like infants or babies.
There is a need for a food product that provides an oral tolerance to allergens.